Oven hood with automatic switch

ABSTRACT

An exhaust hood for use with an oven or the like comprising a shell having a pivotly mounted faceplate carrying on its inner side a cam having an edge of irregular surface contour, a switch in the shell electrically connected between an external source of power and an exhaust fan within the shell, and a pivoted switch actuator or cam follower which at one end engages the irregular surface of the cam and at its other end engages the switch for controlling the switch in correspondence with the position of the actuator on the cam surface.

United States Patent Seidel OVEN HOOD WITH AUTOMATIC SWITCH PrimaryExaminer-Edward G. Favors [75] Inventor: Harry Seldel Menztown Attorney,Agent, or FirmI-larold A. Murphy; Joseph [73] Assignee: RaytheonCompany, Lexington, D. Pannone; John T. Meaney Mass. [22] Filed: Dec.12, 1973 [57] ABSTRACT [21] Appl 2 24 An exhaust hood for use with anoven or the like comprising a shell having a pivotly mounted faceplatecarrying on its inner side a cam having an edge of irregu- [52] US. Cl.98/115 K, 126/299 B lar Surface contour a Switch i the Shellelectrically [51] Int. Cl F23] 11/02 connected between an externalsource of power and [58] held of Search 126/299 299 299 an exhaust fanwithin the shell, and a pivoted switch 126/300 273 A; 98/115 115actuator or cam follower which at one end engages the irregular surfaceof the cam and at its other end [56] References cued engages the switchfor controlling the switch in corre- UNITED STATES PATENTS spondencewith the position of the actuator on the 3,322,] ll 5/1967 Simpson et al98/l 15 K cam Surface- 3,496,704 2/1970 Bandlow 126/299 R X 7 C 4 D3,695,164 10/1972 Stalker 98/115 K rawng fia za F l 36 62 60 L 1.1 l 133 58 40 l L/ p as A A L 56 34 ll 4 t K A 2 44 46 /8 35 /4 0/ FIGPAIENIEUsEP 1 01914 OVEN HOOD WITH AUTOMATIC SWITCH BACKGROUND OF THEINVENTION In the manufacture of exhaust hoods of the characterdescribed, such hoods normally comprise a shell or housing having at thefront thereof a faceplate which is hingedly mounted so that thefaceplate may be lifted to expose the interior of the hood and toprovide access thereto so that changing of a filter, cleaning, oradjusting is made relatively simple. In such devices, a switch isusually mounted on or adjacent the faceplate to provide means wherebythe exhaust fan within the hood can be turned on and off.

However, it will be apparent that in such conventional prior artstructures, cleaning or other procedures taking place within theinterior of the hood might inadvertently or accidently occur while theexhaust fan is being operated. This would easily result in personalinury.

SUMMARY OF THE INVENTION The above and other disadvantages inconventional hoods of the character described are overcome in thepresent invention wherein the faceplate is provided with automaticswitching mechanism whereby the exhaust fan will be activated only whenthe faceplate is open partially to a predetermined extent which is notsufficient to allow easy personal access into the interior of the hood,and will become automatically disconnected from the energizing circuitwhen the faceplate is open sufficiently to permit access for suchcleaning or other operation to take place.

This is accomplished in the present invention by a cam which has anirregularly contoured surface and which is mounted on the inner surfaceof the faceplate for movement therewith, and a cam follower switchactuator which at one end rides on the cam surface and at its other endengages a switch which connects an external source of electrical energyto the fan. The cam surface is contoured such that the switch willremain open in all positions of the cam and faceplate except in oneposition where the cam is provided with an indent or notch in itscontour, this position corresponding to the position desired of thefaceplate when the fan is to be operated. In this position of the cam,the actuator will fall into the indent and allow the switch to beclosed, thus turning the fan on.

Continued further opening of the faceplate will cause consequentmovement of the switch actuator in a manner which will again open theswitch so that the fan motor will be de-energized when the faceplate isopen to an extent which permits personal access to the interior of thehood.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other advantages of thisinvention will become apparent from the following description taken inconnection with the accompanying drawings, wherein FIG. 1 is a frontelevational view of a hood embodying the invention;

FIG. 2 is a front-to-rear vertical sectional view of the hood showingthe novel switch-operating means;

FIG. 3 is an elevational view of the spring detent device; and

FIG. 4 is a view similar to FIG. 2 showing the faceplate in switch onposition.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawings wherein like characters of reference designate like partsthroughout the several views, the hood 10 includes a shell or housinghaving a top 12, a bottom 14, a back wall 16 and sidewalls 18. In thefront of the housing is a faceplate 20 which is hinged at its top edgeas shown at 22 so that it may be pivoted about the longitudinal axis ofthe hinge 22 when manually lifted. The faceplate 20 is shown closed inFIGS. 1 and 2, and is open in FIG. 4.

The hood 10 is particularly intended for use with an oven or the like(not shown) which produces hot combustion products, for example, whichmust be exhausted. Such products normally will enter the hood 10 througha vent 24 in the bottom wall 14 near the front end of the housingrearwardly of the faceplate 20. A fan 26, which is shown schematicallyin FIGS. 2 and 4, will when operated function to draw the combustion orother products from the vent 24 through a filter 28 and then willexhaust the filtered products through a vent 30 in the rear or top wallof the housing.

When the fan is not operating, the combustion products will risevertically from vent 24 and will pass out through a top vent 32.

The fan 26 includes a motor 33 which is adapted to be connected to anexternal source of electrical energy through a switch 34 via wires 36,37 and 38. Switch 34 in conventional hoods is a manually operable devicelocated in a convenient position such as on the faceplate or adjacentexternal portion of the housing.

However, in accordance with the present invention, the switch 34 islocated within the hood and is automatically operable in response tomanual movement of the faceplate. The hood is completely off in thecondition shown in FIG. 2, faceplate 20 being closed, switch 34 off andfan motor 33 deenergized. Switch 34 is a type which is provided with abutton 36 adapted, when pressed, to open the electrical circuit. Whenbutton 36 is released, the circuit is closed to energize the fan motor33 as will be described. Switch 34 may be sup ported upon bottom wall 14or sidewall 18 by means of a bracket 39 or the like.

To operate the switch 34 there is provided a platelike cam 40 which isfixed to the inner surface of the faceplate 20 adjacent one end thereof.Cam plate 40 has on its inner edge an irregularly contoured surfacewhich includes a major surface 42 which is an arc of a circle havinghinge 22 as its center.

Bearing against surface 42 is one end of a spring-held actuator 44 whichis fulcrumed in a bearing bracket 46 fixed upon the bottom or sidewall.A spring 48 attached to the opposite side of the actuator may beemployed to ensure constant engagement of the actuator upon the camsurface 42. However, spring 48 may not always be necessary and thespring tension in the switch may be sufiicient to retain the end of theactuator 44 against surface 42. The other end portion of actuator 44 isretained in engagement with the button 36 of switch 34 and, in thisposition of the actuator, depresses the button, opening the switch andthe associated electrical circuit.

Resilient yieldable means is provided for yieldably retaining thefaceplate in place and comprises a spring-actuated pin 50 (FIG. 3) whichis contained in a housing 52 mounted on the side wall 18 of the hoodhousing. The cam plate 40 is located sufficiently close enough to thewall 18 that it engages the indexing pin 50 and urges it inwardly of itshousing 52 against the tension of a spring 54.

However, when the faceplate 20 is in its closed position as shown inFIG. 2, the pin 50 will engage a small aperture or detent S6 in the camplate 40. Forceful movement of the faceplate upwardly about hinge 22will cause the pin 50 to be depressed and allow the cam plate 40 to movewith the faceplate 20.

This will cause the actuator 46 to ride along the arcuate edge surface42 until it engages a notch 60. Aligned with notch 60 is a second detent62 in cam plate 40. Thus, when the actuator 44 drops into notch 60, theindexing pin 50 will be urged by spring 54 into detent 62, which actioncan be felt by the operator. At the same time, the opposite end portionof the actuator 44 is moved by spring 48 in a direction away from theswitch 34. This causes the switch 34 to operate to close the electricalcircuit to the fan motor 33. Activating the fan 26 will cause thefaceplate to be opened to a point where the hood is most efficient withrespect to air movement before the fan motor is actually switched on.

It will be understood, therefore, that opening of the faceplate to thelimited extent described will turn the fan on. However, the faceplate atthis time is only open a relatively small amount which is not sufiicientto permit a user to readily and easily insert a hand into the interiorof the hood. It will also be understood that if the faceplate 20 isreturned to closed position as shown in FIG. 2, this will cause theactuator 44 to return to the arcuate edge surface 42 of the cam plate40, pivoting in a manner which will depress switch button 36 to open theswitch 34 and stop operation of the motor 33 and fan 26. Thus, thismechanism overcomes the possibility of closing the faceplate with thefan continuing to operate.

A third detent 64 is provided in the cam plate 40 to be engaged by thespring-urged pin 50 when the faceplate 20 is in wide open position. Whenthis occurs, the actuator 44 has progressed out of notch 60 and alongthe cam surface to another high spot or contour 66 where the switch 34will be kept open. Thus, access to the interior of the hood may bereadily and easily achieved with complete assurance that the fan 26 willnot be operated.

From the foregoing it will be apparent that the objectives of thisinvention have been achieved by the described structure wherein a hoodfan or blower is operated in response to positioning of the hoodfaceplate whereby human injury is avoided by rendering the fanautomatically inoperable when the faceplate is open sutficiently toallow access to the interior of the hood.

It is to be understood, however, that various modifications and changesmay be made by those skilled in the art without departing from thespirit of the invention as expressed in the accompanying claims.Therefore, all matter shown and described is to be interpreted asillustrative and not in a limiting sense.

I claim:

1. An exhaust hood comprising a housing including a pivotal faceplate, afan within the housing, switch means for connecting the fan to anexternal source of electrical power, movable means connected to theinterior side of the faceplate and movable in response to pivotalmovement of the faceplate, connecting means connected between saidmovable means and the switch means and operable in response to movementof the movable means to operate the switch means in response to suchmovement.

2. An exhaust hood as set forth in claim 1 wherein said movable means isa cam rotatable in a vertical plane to a plurality of predeterminedpositions, the connecting means is a member held constantly inengagement with the cam, and the switch means is operable in response topositioning of the cam as determined and translated to the switch meansby said member.

3. An exhaust hood as set forth in claim 2 wherein restraining means ismaintained in engagement with said cam for yieldably retaining saidfaceplate in adjusted position.

4. An exhaust hood comprising a housing including a faceplate movablefrom a closed position to a wide open position through at least oneintermediate position, a fan in said housing, switch means forconnecting the fan to an external source of electrical power, andswitch-activating means connected between said switch means and saidfaceplate for operating said switch in response to movements of thefaceplate into and out of said positions, said restraining meanscomprising a disclike member fixed to the faceplate and extendinginwardly of the housing adjacent a portion thereof, and spring meanscarried by said portion of the housing and engaging said member.

5. An exhaust fan as set forth in claim 4 wherein said member isprovided with indexing means corresponding to selected positions of thefaceplate, and said spring means is located to engage said indexingmeans in response to movement of the faceplate.

6. An exhaust fan comprising a housing including a faceplate movablefrom a closed position through at least one intermediate position to awide open position, a fan in said housing, switch means for connectingthe fan to an external source of electrical power, and switch-actuatingmeans connected between said switch means and said faceplate foroperating said switch means in response to movements of the faceplateinto and out of said positions, said switch-actuating means comprising acam plate fixed to the faceplate and having an irregular surfacecontoured to correspond to said positions of the faceplate, and apivotal actuator having a first end portion in engagement with saidirregular surface and an opposite end portion connected with said switchmeans for actuating the switch in response to movement of the first endportion of the actuator as it is moved by said irregular surface whenthe cam plate is moved.

7. An exhaust hood as set forth in claim 6 wherein restraining means islocated between said cam plate and an adjacent portion of the housingfor yieldably retaining the faceplate in adjusted position.

1. An exhaust hood comprising a housing including a pivotal faceplate, afan within the housing, switch means for connecting the fan to anexternal source of electrical power, movable means connected to theinterior side of the faceplate and movable in response to pivotalmovement of the faceplate, connecting means connected between saidmovable means and the switch means and operable in response to movementof the movable means to operate the switch means in response to suchmovement.
 2. An exhaust hood as set forth in claim 1 wherein saidmovable means is a cam rotatable in a vertical plane to a plurality ofpredetermined positions, the connecting means is a member heldconstantly in engagement with the cam, and the switch means is operablein response to positioning of the cam as determined and translated tothe switch means by said member.
 3. An exhaust hood as set forth inclaim 2 wherein restraining means is maintained in engagement with saidcam for yieldably retaining said faceplate in adjusted position.
 4. Anexhaust hood comprising a housing including a faceplate movable from aclosed position to a wide open position through at least oneintermediate position, a fan in said housing, switch means forconnecting the fan to an external source of electrical power, andswitch-activating means connected between said switch means and saidfaceplate for oPerating said switch in response to movements of thefaceplate into and out of said positions, said restraining meanscomprising a disclike member fixed to the faceplate and extendinginwardly of the housing adjacent a portion thereof, and spring meanscarried by said portion of the housing and engaging said member.
 5. Anexhaust fan as set forth in claim 4 wherein said member is provided withindexing means corresponding to selected positions of the faceplate, andsaid spring means is located to engage said indexing means in responseto movement of the faceplate.
 6. An exhaust fan comprising a housingincluding a faceplate movable from a closed position through at leastone intermediate position to a wide open position, a fan in saidhousing, switch means for connecting the fan to an external source ofelectrical power, and switch-actuating means connected between saidswitch means and said faceplate for operating said switch means inresponse to movements of the faceplate into and out of said positions,said switch-actuating means comprising a cam plate fixed to thefaceplate and having an irregular surface contoured to correspond tosaid positions of the faceplate, and a pivotal actuator having a firstend portion in engagement with said irregular surface and an oppositeend portion connected with said switch means for actuating the switch inresponse to movement of the first end portion of the actuator as it ismoved by said irregular surface when the cam plate is moved.
 7. Anexhaust hood as set forth in claim 6 wherein restraining means islocated between said cam plate and an adjacent portion of the housingfor yieldably retaining the faceplate in adjusted position.